Method of making fluid-tight packing pieces



y 1942; J. MERCIER 2,281,780

METHOD OF MAKING FLUID-TIGHT PACKING PIECES Filed Sept. 2, 1939 Jean Mercier INVENTOR HIS ATTORNEY Patent ed May 1942 Es PATENT 'QFFI Ma'mon came FLUID-TIGHT g PACKING rmcns Jean Mercier, Neuilly-sur-Seine, France .pplication September 2, 1939, serial No. 293,199

In Lnxe nburg October 22, 1 938 7 claims. (c1. 29-1565) The presenemvehtionfremes to a method of makings packing piece having an annular elastic.

lip adapted to bear, against a convex or concave surface so asto forma movable fluid-tight parti-,

tion along. said surface.

The object of my.invention is to provide a method -ofthis kind which is both simpleand' According to a feature of myv invention, v this method includes machining a cylindrical blank so as to form a lip of bevelled axial section,truncating the 'end portion of saidf lip,-and deforming the truncated end portion so asto cause it to project beyond the cylindrical surface of the lip, while mechanically hardening, this truncated end portion.

Preferably, this mechanicalhardening is produced bythe same operation which effects the desired deformation.

The piece thus prepared is ready to be mounted. It willbe observed that the various operations for the manufacture ofsaid packing piece according to the invention are of a very simple nature, and they will thus provide for a most economical manufacture on a large scale.

A preferred embodiment of the present invention will be hereinafter described with reference to the accompanying drawing given merely by way of example, and in which:

Fig. 1 shows the mounting of the blank in a lathe;

Fi s. 2 to 4 are partial cross-sections showing three different and successive stages of the packs p ece:

Fig. 5 shows the relation of the packing piece with respect to the surface against which it is to be applied.

As shown in Fig. 1, the blank I from which the said packing device is to be formed and consisting of a metal bar, a tube, a cylinder or the like, is placed between jaws 2 ofa lathe. In Fig. 1, it has been supposed that the packing device has already been rough-cut from a round barthe central part of which has been provided with ahole in order tq form the lip 1. It will be noted that the section of the lip decreases the outer edge of the lip. The angle a at the vertex is preferably comprised between 8 and 15, for instance, for diflerences of pressure ranging from 0 to 500 kgs. Obviously, carewill be taken to give the lip a certain thickness in order that it will have the proper strength.' This angle a is usually given a value which is greater according as the diameter,- or the difference between the pressures inthe two spaces to be separated by the packing piece, or both, are greater.

The outer end of the lip is then cut oil by a suitable tool, preferably a diamond milling cutter, in such way 'as to give the lip, in section, a

- quadrangular form (Fig. 3), the fourth face 6 thus formed being so inclined "as to form with the contact surface l an angle a which is preferably comprised between 30? and 60;

The-surface 6 of the outer edge of the lip is then subjected to a pressure in the direction of the arrow j, for instance by means of the cutting tool itself, or by any other suitable device, such a as a rolleror a small wheel running on said 1 the entire length of the edge, thus producing the desired projection and deformation. This may have a certain importance when the packing piece is mounted on a lathe and when it is desired to obtain the deformation while at the same time continuing to rotate the piece on the lathe. This method of operation is quite simple and economical, and moreover, there is no risk of tearing on the material of the lip. It isevident that the roller tool will beapplied against the packing piece with the proper pressure.

The pressure thus exerted will cause a deformation of the outer part I of the lip} and hence the latter will form a nose or a beak or simply an outstanding portion which projects, as shown in Fig. 4, beyond the cylindrical surface 3' of the lip. This deformation serves not only to form the nose I, but also to produce a surface hardening of the end part I of the lip. Thus the metal of the packing piece, in this part, a greater hardness-and rigidity.

When the packing piece is then mounted on the devices between which a fluid-tight joint is to be obtained, the lip 3 becomes slightly curved below the hardened end part, as shown in Fig. 5.

In fact, the nose I which projects from the surface 3 is pressed back by the contact surface 8' of the device 8.

This forms a small space between the surfaces 3 and 8 below the nose I, and it is only this sharp edge I of this nose that is applied with force against the contact surface thus affording the desiredfiuid-tight joint.

Obviously, the'invention is not limited, to the embodiment herein described and represented,v

which is given solely by way of example.

For instance, the packing piece may consist of any elastic material, and chiefly of a suitable metal or alloy such as bronze, nickel or glucinium bronze, steel bronze, or other suitable metals or alloys (silver, brass, copper, etc.) A packing piece of rubber or the like may also be employed, in which the end of the lip can be metallized.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A method ofmanufacturing a packing piece of the type described which comprises starting from a cylindrical blank,machining said blank so as to form, at one end thereof, an annular lip of bevelled axial section, cylindrical on one side thereof and conical on the other side. cutting off the end portion of said annular lip so as to trun cate it along a conical surf-ace coaxial with said conical side of said lip and of the same direction but of greater apex angle. deforming the truncated end portion of said lip so as to project beyond the cylindrical surface thereof in the direction of the part with which the packing piece is to cooperate in a fluid-tight manner and mechanically hardening this end portion of the lip. 2. A method of manufacturing 'a packing piece of the type described which comprises starting from a cylindrical blank, machining said blank so as to form, at one end thereof, an annular lip of bevelled axial section, cylindrical on one side thereof and conical on the other side, cutting off the end portion of said annular lip so as to truncate it along" a conical surface coaxial with said conical side of said lip and of the same direction but of greater apex angle, and deforming the truncated end portion of the lip so as to cause it to project beyond the cylindrical'face thereof, in the direction of the part with which the packing piece is to cooperate in a fluidtight manner, this deforming operation being performed in such manner as to harden this end portion of the annularlip.

3. A method according to claim 2 in which the deforming operation is performed by means of the same tool that has been used for cutting off the end portion of the annular lip.

4. A method according to claim 2 which com-= prises performing the machining operation on a lathe, cutting off the end portion of the-lip as the piece is still on the lathe, and deforming the truncated end portion of the lip by means of a tool including at least one roller arranged to run on the annular edge formed when cutting oil the end of the lip.

5. A method according to claim 1 in which the deformed end portion of the lip is caused to project beyond the cylindrical surface of the lip a distance ranging from one to two tenths of a millimeter for a packing piece of a diameter ranging from 40 to millimeters.

6. A method according to claim 2 in which said blank is made of metal:

'7. A method according to claim 2 in which said blank is made of rubber havinga metallized end portion.

JEAN MERCIER. 

